大规模MIMO户外测量及信道研究

发布时间：2018-03-28 20:49

本文选题：大规模MIMO　切入点：信道测量　出处：《西安电子科技大学》2015年硕士论文

【摘要】：随着4G进入大规模商用阶段,下一代的无线数据网络或被称作第五代移动通讯技术5G的研发正在如火如荼的开展。Massive MIMO技术作为5G中的关键技术,受到业界各研究机构的重视,成为如今5G技术研究的热点。所谓的Massive MIMO指的是在收发端配置了数十根或上百根天线同时服务数十个用户,而用户终端采用单天线接收的通信方式,研究表明Massive MIMO技术能显著地提高无线通信系统的性能,如大幅度提高系统容量和能量效率、有效地降低小区内的干扰、系统建设成本低廉等。本文以Massive MIMO技术为课题,重点对Massive MIMO的信道进行了研究。无线信道是移动通信的传输媒介,它是进行无线通信系统设计、相关技术研究的基础。为了有效地获得Massive MIMO无线信道的特性,需要对信道进行实际测量。基于实际测量数据,提取出无线信道参数进行研究分析,借由这些参数反映出Massive MIMO的信道特征,并可为Massive MIMO信道理论模型的建立提供有力的帮助,为信道建模提供参考和比对,以此来验证信道模型的准确性与合理性。本文的主要工作是对Massive MIMO信道进行实际的测量,并对测量数据进行数据处理和分析。首先,针对Massive MIMO信道的特点,构建出具体的室外测量方案,选购相关测量仪器如示波器、信号发射源等来搭建实际测量平台。根据一般信道场景的分类,在西电校园内选取了8个测试地点,其中4个为LOS场景,4个为NLOS场景,发端分布在这8个测试点上。其次,在收端采用了128阵元虚拟的天线线性阵列来进行信道测量。其中采用了扩频滑动相关信道测量法,在发端发送已调制的伪随机序列,在收端将接收信号存储至计算机进行数据处理。本文详细描述了Massive MIMO信道实际测量的流程。最后,对测量数据进行数据处理,提取了4个信道参数进行分析。它们分别是莱斯K因子、角度功率谱、用户间信道相关系数、信道特征值分布。通过实际测量发现,随着天线数目增大,K因子随着阵元位置剧烈变化、用户信道间的相关性减小、信道增益趋于稳定、多径的生灭等,这些研究发现体现出Massive MIMO信道的非平稳性和Massive MIMO所带来的优势,还能为Massive MIMO理论模型的建立提供参考。此外,本文还对Massive MIMO信道中多径的生灭变化速率进行了研究,基于实际测量数据推导出多径的生灭速率与信道冲激响应之间的关系。
[Abstract]:With 4G entering the large-scale commercial stage, the next generation wireless data network, or 5G, which is called the fifth generation mobile communication technology, is developing in full swing as the key technology of 5G. The so-called Massive MIMO means that dozens or hundreds of antennas are deployed on the transceiver to serve dozens of users at the same time, and the user terminal uses a single antenna to receive the communication. The research shows that Massive MIMO technology can significantly improve the performance of wireless communication system, such as greatly improving the system capacity and energy efficiency, effectively reducing the interference within the cell, and the system construction cost is low. This paper focuses on Massive MIMO technology. The channel of Massive MIMO is studied in detail. Wireless channel is the transmission medium of mobile communication, it is the basis of wireless communication system design and related technology research. In order to obtain the characteristic of Massive MIMO wireless channel effectively, Based on the actual measurement data, the wireless channel parameters are extracted to reflect the channel characteristics of Massive MIMO, which can provide powerful help for the establishment of Massive MIMO channel theoretical model. It provides reference and comparison for channel modeling to verify the accuracy and rationality of the channel model. The main work of this paper is to measure the Massive MIMO channel, and to process and analyze the measured data. According to the characteristics of Massive MIMO channel, a specific outdoor measurement scheme is constructed, and relevant measuring instruments such as oscilloscope and signal emitter are selected to build the actual measurement platform. Eight test sites were selected in the West Electric Power Campus, of which four were LOS scenarios and four were NLOS scenarios. The starting point was distributed on the eight test sites. Secondly, A linear array of 128 arrays of virtual antennas is used to measure the channel at the receiving end, in which the spread spectrum sliding correlation channel measurement method is used to transmit the modulated pseudorandom sequence at the beginning. At the receiving end, the received signal is stored to the computer for data processing. In this paper, the actual measurement flow of the Massive MIMO channel is described in detail. Finally, the measurement data are processed. Four channel parameters are extracted for analysis. They are Rice K factor, angle power spectrum, channel correlation coefficient and channel eigenvalue distribution among users. With the increase of the number of antennas, the correlation between the user channels decreases, the channel gain tends to be stable, and the multipath becomes extinct and so on. These findings reflect the non-stationarity of Massive MIMO channel and the advantages of Massive MIMO, and can also provide a reference for the establishment of Massive MIMO theoretical model. In addition, this paper also studies the rate of multipath variation in Massive MIMO channel. The relationship between multipath birth and death rate and channel impulse response is derived based on actual measurement data.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN919.3

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